Approach #1: Get bigger shoes
I was wearing a size 5 shoe, which is the same size shoe that I wear when I'm not running. We've all heard the advice - size up at least a half size, maybe even a full size for running. So I finally broke down and got a size 5.5. I don't know why I've been so resistant to this. The larger shoes feel better, but the numbness hasn't gone away. And a 6 really is too big.
Approach #2: Experiment with lacing
Loosening my laces can help take some of the pressure off. I've also tried various lacing patterns that are designed to reduce the pressure. Below is the most recent lacing pattern I was trying. The laces run parallel until the forth pair of eyelets. Again, it seemed to help, but not enough. I had to stop several times during miles 4-6 to keep loosening my laces. By the end my feet were still numb and I was surprised I wasn't running right out of my shoes they were so loose!
Approach #3: Lock laces
I am now the proud owner of a pair of lock laces. They are no-tie elastic laces and some folks have found them helpful for numbness. I had a bit of trouble getting them into my shoes (the eyelets were too narrow for the laces), but cutting off the tips helped with that. I wasn't sure if I should try an alternate lacing pattern designed to reduce pressure or go with the regular pattern. I laced them using the Lydiard lacing approach and found they were ridiculously loose, so I went with the standard pattern. You can see my new laces below: